1. Field of the Invention
The present invention relates generally to a lock down device, and more particularly to a device for securing items to a structure.
2. Related Art
Computers, particularly IBM-compatible computers, often use expansion cards to add functions not performed by the computer's motherboard. Typical expansion cards have contact portions that are inserted into expansion slots of a computer's motherboard. Common expansion cards include, for example, graphics cards, video adapter cards, internal modem cards, sound cards, disk drive controller cards, network interface cards and the like.
Early personal computers (also sometimes referred to as microcomputers) often used full-length expansion cards that were inserted into the motherboard's expansion slots and secured at both ends with screws to the computer's chassis. Over time, manufacturers continuously improved expansion cards, adding more features and significantly reducing their size, particularly the length and the height, of the cards. Today, these smaller more powerful expansion cards are often secured with a single screw to one side of a computer's case (also referred to as a chassis).
Additionally, due to the increasing speed of modern computers and the growing demand for more realistic and faster graphic displays, manufacturers of graphics processing units (GPUs) have been advancing graphic card technology to support the ever increasing graphics performance demands of garners, visualization and simulation users (for example, medical devices), CAD users, and others. Further, current graphics cards are designed for insertion into either Accelerated Graphics Port (AGP) or Peripheral Component Interconnect (PCI) Express motherboard connections (i.e., AGP or PCI Express Interfaces). As these graphics cards have grown more powerful, their power consumption has increased, thereby generating more heat within the computer. For example, some of the more powerful graphics cards use as much power as the computer's central processing unit (CPU), and have their own heat sink and fan, which adds additional mass and weight to the cards.
To counter the heat generated by the more powerful graphics cards, some cards are liquid cooled. One popular design uses tubes at the top of the card to circulate liquid through the heat sink. The use of liquid cooling, however, adds additional mass and weight to the cards.
These more powerful and often heavier expansion cards have increased service costs for manufacturers, assemblers and resellers of personal computers. For example, the securing method for these cards (e.g., a single screw) often does not sufficiently retain and/or stabilize the card. As such, it is not uncommon for expansion cards to dislodge and/or break during manufacturing, packaging, transportation, and/or physical movement of the assembled computer. To counter this, lock down devices have been manufactured to help secure these expansion cards to the computer case.
U.S. Pat. No. 6,017,004 discloses one prior art computer card lock down device for securing expansion cards to reduce the likelihood of the card becoming wholly or partially dislodged during shipment. Although this device provides some protection for standard cards, it is not readily adaptable for use with the new, heavier, liquid cooled cards.
U.S. Pat. No. 6,256,191 discloses a second lock down device for securing an expansion card. This device uses a compression spring in securing the card. This device, however, is likewise not easily readily adaptable for securing heavier liquid cooled cards.
In addition to these prior art lock down devices being deficient in securing liquid cooled expansion cards, they are further deficient for securing two or more interconnected expansion cards (referred to as dual or quad card configurations). For example, to meet growing demands for improved graphics and system performance, graphics manufacturers have developed technologies permitting two or four graphics cards to be installed in a single system that are able to work together to offer improved graphics performance. Such graphics technologies include NVIDIA's SLI dual and quad graphics card technologies and ATI's Crossfire dual graphics card technology. These technologies typically require a bridge that connects the multiple (e.g., two) graphics cards. Although, this bridge provides an electrical connection between the cards, it offers little, if any, rigidity and, itself, may become dislodged during movement of the system if not properly retained. Further, the bridge may raise the profile of the graphics card above the edge of the graphics card, thereby preventing proper seating of prior art lock down devices. As such, there is a need for new and improved lock down devices.